Dry cleaning establishments are commonplace the world over and have, for many years, provided valuable services in cleaning, sanitizing and restoring fabrics and clothing garments which are not suitable for laundering operations. While the specific machinery used in such dry cleaning operations varies somewhat, generally all utilize a closed drum having a rotatable tumbling basket disposed therein for receiving a quantity of clothing or the like for dry cleaning. The drum is usually equipped with an access door which is closed and preferably sealed during cleaning operations. The basic cleaning cycle involves the introduction of cleaning solvent into the drum and basket which is circulated through various filters as the tumbling basket is agitated or rotated to tumble the clothing articles through the solvent. At some point, usually under the control of a master timer, the solvent is extracted in a cycle which culminates in a high speed spin operation. Next, heated air is circulated through the basket and clothing articles in a drying cycle. Frequently, the air used in the drying cycle is heated before it passes through the clothing, then cooled to condense solvent out of the air and finally reheated prior to the next circulation through the drying clothing. Following the drying cycle, a reduction or cool down cycle is the final step in the dry cleaning process.
When first used, such dry cleaning operations were conducted without concern for the environment. Thus, in many early dry cleaning machines, the circulated air was simply vented to the atmosphere to carry away the solvent during the drying operation. However, recent environmental laws and regulations have imposed very strict constraints upon dry cleaning operations. In general, these regulations and laws have mandated the use of closed systems which do not permit the venting of solvent into the atmosphere. In addition, current environmental laws and regulations mandate more efficient solvent recovery throughout the entire dry cleaning operation in response to concerns over solvent emissions during loading and unloading as well as solvent residues remaining in clothing at the completion of the dry cleaning cycle.
The goal of many of the recently enacted laws and regulations is the reduction of solvent contaminants in both the environment at large and the dry cleaning establishment to prevent adverse effects to the health and well-being of workers in such establishments. These regulations are particularly difficult to meet in busy dry cleaning establishments which may utilize multiple dry cleaning machines and which store substantial quantities of recently cleaned clothing. Thus, measurements directed to total solvent emissions within the air at the cleaning facility essentially monitor the cumulative effect of many solvent emission sources.
While presently available dry cleaning systems meet current environmental and workplace safety regulations, they do so only if properly maintained and operated. In view of the clear trend of environmental laws and regulations as well as workplace safety laws toward stricter and more demanding requirements, it is clear that improved dry cleaning systems will soon be required. Thus, there is a continuing need in the art for environmentally sound dry cleaning systems. It would be an additional benefit if such systems provided cost and quality benefits as well.